I've stayed at both hotels suites as a Diamond and loved them both. Service was top notch at both hotels.

I would give the nod to the PHT for its breakfast, especially the Japanese one. But the Conrad has the Exec Lounge with wonderful free drinks and appetizers in the evening. The appetizers rotate from the different hotel restaurants - e.g. Gordon Ramsay one night, Japanese another night, etc.

Our suite at the PHT had a view of Mount Fuji. PHT also lets you request complimentary mini-Shisheido toiletries. The Conrad has the bears and the rubber duckies (as mentioned by someone else) and a better location. It is near the fish market, Ginza, and the trains.

The Conrad will always hold a special place in my heart because I was staying there during the 2011 earthquake. Every staff person expressed a genuine concern for the guests to ensure that everything operated smoothly.

If I had to choose, I would probably alternate between the two hotels.